Work machines such as agricultural tractors are commonly used to tow implements behind them for various purposes, including planting and tilling. Hitches are commonly incorporated on the back of a tractor to provide the point of attachment for coupling the implement to the tractor. Such hitches have been designed to provide movement of the implement relative to the tractor through hydraulic or other mechanisms operated by a control system or the tractor operator. Controlling the implement is important so that turning and other desired operations can be readily accomplished.
Accordingly, control devices are used in conjunction with electronic systems to allow the position of the implement to be monitored and automatically controlled during operation. To date, the devices and systems have been used to monitor and control position and draft. The position controls are used for raising and lowering of the implement coupled to the hitch, while draft controls adjust the position of the implement to optimize the force that the implement exerts on the machine during operation. These systems utilize devices that monitor one or more components of the hitch such as draft arms, lift arms, or the pitch link for generating a signal indicative of position or force. The devices require a linkage to couple various sensors between the machine and the hitch or position sensors located directly in a connector or pin. One such device is disclosed in U.S. Pat. No. 5,682,954 issued Nov. 4, 1997 and assigned to the Case Corporation Racine, Wis. This arrangement uses a strain gage positioned in the upper pivot pin of the pitch link and sends signals to a control system representative of the force exerted on the work machine by the implement under tow. However, none of the previous arrangements or control systems have been used to accurately monitor the side to side or pivotal position of the draft arms to aid in hitch assisted steering.
The present invention is directed to overcoming one or more of the problems as set forth above.